It has been conventional practice to test engine parts such as cylinder heads and blocks to detect leaks in the cooling jacket by sealing openings leading to the cooling jacket with a single plate and gasket to seal off the head gasket area of the head or block. The plate is secured by bolts threadedly engaged with complemental openings in the head or block. Air is then injected into the cooling jacket following which a soap solution is used to detect leaks, cracks, etc.
Apparatus of the above type is limited in usage because one plate fits only one application and many different sizes and lengths of bolts are required to secure the same to the engine cylinder head or block. By employing a solid plate and gasket, it is furthermore impossible to see all problem areas of the part being tested.
In U.S. Pat. No. 3,360,984 granted to H. I. Salsbury et al on Jan. 2, 1968, there is disclosed a universal testing apparatus for cylinder heads which is applicable to a greater variety of engine parts. In this device, individual sealing members are placed over the cooling jacket openings, the sealing members in turn being clamped to a stand placed over the engine part. The stand necessarily limits the size and type of engine part that can be tested because of numerous differences in sizes of engine cylinder heads and blocks.
The Salsbury apparatus furthermore is designed for fluid pressure testing wherein, as noted above, air under pressure is injected into the cooling jacket, following which a soap solution is applied to the cylinder block for detecting leaks or cracks.
It has been found, however, that this type of test is not always dependable since air pockets sometime develop within the cooling jacket in the area of the leak and, consequently, the leaks do not show. Also, applying a soap solution to a cylinder head or block can result in missing a crack that is not accessible.
A preferable and more dependable type of testing has been developed wherein air is injected under pressure into a sealed water jacket of a cylinder head or block and then the engine part is submerged in a hot water vat whereby air bubbles are immediately visible where there are any cracks in the engine head or block.
In view of the necessity of employing a stand in conjunction with the sealing members in the Salsbury apparatus, it is virtually impossible to use the Salsbury apparatus in testing an engine part by submerging it in a hot water vat.